Everyone recognizes Amazon's famous logo. But did you know there are three different symbolic messages tucked within it?

We picked 17 tech company logos that have hidden, subtle, or otherwise clever messages inside their famous brand marques. They include a Facebook logo that secretly indicates another company it hoped to kill, a message you won't get unless you understand Morse, and an actual cryptogram.

In Sony's Vaio logo, the letters V and A represent an analog waveform and the I and O represent a binary code.

Image credit: Sony

Facebook Places was Facebook's now defunct response to the check-in app Foursquare. Note that the red arrow is pointing at a number four ... an indicator of its intended target.

Image credit: Facebook

We love the Skitch logo because it looks like the feathers on an arrow, but those fletchings double as an S and its reflection.

Image credit: Skitch

Cisco's logo represents a digital signal that happens to take the form of the Golden Gate bridge, which is in San Francisco, the city after which the company is named.

Image credit: Cisco

You've probably noticed that Amazon's logo contains a yellow arrow that doubles as a smile, but did you also notice that it points from A to Z?